A Unique Potato Virus Collection
|| If a plant pathologist, breeder, geneticist, or
grower discovered an unusual viral disease in a potato crop, where could that
person go to identify the culprit?
One good place to check would be the Agricultural Research Service's Schultz
Potato Virus Collection, named after ARS plant pathologist Erwin S. Schultz. He
and plant pathologist Donald Folsom, with the Maine Agriculture Experiment
Station, started this collection in 1916 at Aroostook State Farm at Presque
Researchers throughout the world have compared their infected potato plants
with those maintained in the Schultz collection. Even nowafter more than
80 yearsthe collection still contains progeny from the original infected
Names given to the infectious diseases maintained in the collection were based
on descriptive symptoms of so-called degeneration diseases of potato hosts.
Scientists showed that diseases such as Aucuba mosaic, calico mosaic, latent
virus, leaf rolling mosaic, mild mosaic, rugose mosaic, and severe mosaic are
viral in nature.
In 1971, ARS researchers determined that a viroid was the cause of potato
spindle tuber disease, which previously had been identified as a virus.
Materials from the Schultz potato virus collection were used to identify these
Plant pathologist Robert W. Goth, who has been curator since 1968, maintains
the collection, now housed at Aroostook Farm and at ARS' Vegetable Laboratory
in Beltsville, Maryland.
"Since 1930, viral reactions of many potato cultivars released jointly by
USDA and cooperating agencies were evaluated using samples from this
collection," says Goth.
Viruses are maintained in plants grown in insect-proof cages to avoid
contamination and loss of original viruses. Each year, the virus-infected
plants are grown out in these small, screened cages in the field to keep the
collection going for future use. Goth saves four tubers from each cage for
replanting at Presque Isle the next year and sends the remaining tubers to
Beltsville for further use and study. All of the potato viruses in the
collection are those most prevalent in the United States, Canada, and Europe.
"Interestingly," says Goth, "some pathogens in the collection
affect not only potatoes, but other crops as well." Potato virus Y, for
example, which can be spread by aphids, also affects tobacco, tomatoes,
peppers, and many other plants.
"The collection continues to grow," Goth notes. A new Carla
virusisolated from the potato variety Red Lasoda in 1992 and named
"potato latent virus" in 1998was added to the collection this
year. Researchers can request samples of any virus in the collection.By
Weaver-Missick, Agricultural Research Service Information Staff.
Robert W. Goth is with the
Laboratory, Rm. 240, Bldg. 10A, 10300 Baltimore Ave., Beltsville, MD
20705-2350; phone 301-504-5953, fax 301-504-5555.
"A Unique Potato Virus Collection" was published in the
issue of Agricultural Research magazine.